from rest_framework import serializers

from goods.models import SKU


class CartSerializer(serializers.Serializer):
    sku_id = serializers.IntegerField(label='sku_id', min_value=1)
    count = serializers.IntegerField(label='数量', min_value=1)
    selected = serializers.BooleanField(label='是否勾选', default=False)
    
    def validate(self, data):
        try:
            sku = SKU.objects.get(id=data['sku_id'])
        except SKU.DoesNotExist:
            raise serializers.ValidationError('商品不存在')
        if data['count'] > sku.stock:
            raise serializers.ValidationError('商品库存不足')
        
        return data


class CartSKUSerializer(serializers.ModelSerializer):
    """
    购物车商品数据序列化器
    """
    count = serializers.IntegerField(label='数量')
    selected = serializers.BooleanField(label='是否勾选')
    
    class Meta:
        model = SKU
        fields = ('id', 'count', 'name', 'default_image_url', 'price', 'selected')


class CartDeleteSerializer(serializers.Serializer):
    sku_id = serializers.IntegerField(label='商品id', min_value=1)
    
    def validate_sku_id(self, sku_id):
        try:
            sku = SKU.object.get(pk=sku_id)
        except SKU.DoesNotExist:
            raise serializers.ValidationError('商品不存在')
        return sku_id


class CartSelectAllSerializer(serializers.Serializer):
    """
    购物车全选
    """
    selected = serializers.BooleanField(label='全选')
